


A Guide to Underlinging

by andalucite



Category: Teen Wolf (TV)
Genre: As in Derek sweetheart get it together you oblivious creature, Courtship, Getting Together, M/M, Murder Husbands + Murder planning husband, N O W K I S S, Sugar dynamics, Uncle/Nephew Incest, all fluff! all comfort! the murder is an expression of love and in the background!, very informal writing style/Derek Hale's Internal Monologue
Language: English
Status: Completed
Published: 2019-01-06
Updated: 2019-01-06
Packaged: 2019-10-05 16:32:29
Rating: Teen And Up Audiences
Warnings: No Archive Warnings Apply
Chapters: 1
Words: 3,108
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/17328548
Author URL: https://archiveofourown.org/users/andalucite/pseuds/andalucite
Summary: Derek is just glad this is not a new vendetta on either Peter or Stiles' part and is helping because he's bored, that's all





	A Guide to Underlinging

**Author's Note:**

  * For [twothumbsandnostakeincanon (somanyofthekids)](https://archiveofourown.org/users/somanyofthekids/gifts).



> First posted on tumblr attached to an ask for twothumbs, now with a lot more content! ANd my first Teen Wolf fic which I honestly never saw coming even though this fandom is amazing

Derek and Peter are living together in semi-comfortable harmony because these days Derek and Peter are good, they’re totally chill, things have been hashed out, and Derek is happy with how things are. Which is to say Derek will never be that much better at using his words instead of (or even concurrently with) his eyebrows and Peter will never be that much better at not killing people who may or may not deserve it, but it’s okay.

Because Peter has killed a bunch of people and is still killing people but these days he’s good, or at least good about it and tells Derek when he’s going to kill people, especially if he’s killing people that don’t immediately have it coming. And, look, Derek can and does agree that a good offense is the best defense but sometimes Peter’s idea of a good offense forgets about the defense part and sometimes that can come back around to bite both of them in pretty spectacular ways.

Derek used to get around that by just always expecting it, but these days Peter is better, he’s good (for a very narrow Peter-specific definition of good anyways), and he talks to Derek about life things even when Derek is not necessarily up for talking back.

Only.

Peter is definitely killing a bunch of random people right now and he is also not telling Derek that he’s doing it. In fact, he’s being downright sneaky about it. Which. Could be a new vendetta, either by or against Peter (most likely by, see Peter’s proactive approach to self-defense), which would be very bad all around, not least because Derek likes to sleep in his room which is mere feet from where Peter usually sleeps and they’re both vulnerable in their sleep and taking watch shifts all night with just two people is kind of a lot.

And requires the two people to talk about why they might hypothetically need to be taking all night watch shifts so that said shifts can be established and the right kind of coffee can be bought.

Anyways.

Derek is not _worried_ , per se, because he trusts Peter these days, but.

Well.

He’s also not stupid, so he calls Stiles to ask about any possible Peter-vendettas. Which is really the most rational first step, because Derek watches Peter a lot but Peter is not the only one he watches and Stiles also watches. Peter. Stiles watches Peter who Derek also watches but sometimes watches Stiles watch? Which makes Derek’s head hurt to think about, but point is Stiles almost always knows what Peter is up to because Peter loves nothing more than an appreciative audience and there is only so much shock and awe that Derek can convey with his eyebrows before needing to tag Stiles in with something to actually say. Like no, stop, maybe think through killing the barista (who is underpaid and likely innocent due to not being the one to greenlight sub-par breakfast pastries) and go after the owner instead (who is the one doing both the underpaying and the greenlighting, Peter, think about it!).

But calling Stiles is way less helpful that Derek is anticipating, because he first has to sit through almost the entire ringtone for Stiles to answer and then when he asks about Peter Stiles kind of sounds like he is choking as he says no, nah, nothing’s up, Peter’s totally chill right now, why, did something happen? And vendetta is such a strong word for anything that Peter could get up to which is not denying that he totally has called multiple vendettas with body counts in the triple digits before but that was yesterday! And today is a new day! New Peter! Well, the same Peter not like he’s been body-snatched and pod-person’d, but, like, vendetta-free Peter, totally-normal-murdering Peter, who is not murdering right now as far as Stiles knows and if he was that’d be probably okay because Peter knows how to pick up after himself now? And anyways oh hey look at the time oh my gosh is it that late I’ve got to call a man about some pants before the banks—well, nothing, actually, Peter’s fine don’t worry and don’t tell him you talked to me about it you know how he gets about behind-his-back talk and there was already that thing last week—

What.

Oh god, is this _Stiles’_ vendetta that Peter is helping with? Peter goes exactly as far as (he perceives as) necessary with his own business, goes slightly overboard with Derek’s business, and Derek has a headache just considering how far overboard (multiple no-warning nuclear strikes comes to mind with literally zero effort) Peter would go for Stiles. His headache seems like it would not appreciate further contemplation on why Stiles would need a man and a bank to be involved with a pair of pants—that sounds like something Peter would be better suited to handle—so Derek chooses to just ignore that bit altogether.

Not even mentioning how bad a Stiles-based vendetta would be. The mass grave that is Peter’s vengeance would likely end up looking like child’s play if Stiles comes to bat. ( _With Peter_ , oh holy god.)

So he goes to ask Peter about it. If Peter knew how round-about Derek was being, he’d be so proud. Sadly, being round-about necessitates Peter not knowing.

Point is, Derek does _not_ ask why Peter is being weird.

He asks Peter why Stiles is being weird.

This is much more effective, because Peter immediately starts being weird out in the open where Derek can see it, which is much more enlightening.

Peter physically stutters over making his coffee, draws up like an offended cat, and just lays into Derek (Peter may or may not have slept that night and Derek may or may not have intentionally gotten him at his worst. It’s just basic talking-to-Peter measures, really). Like, what do you mean Stiles is being weird, he should be totally fine, in fact, better than fine, because his week should be clear now that certain—never mind that, the next month should be all good for Stiles because he needs to be focused on other things right now and Peter had made sure—well, anyways, what does being weird mean, Derek, Stiles is always weird get a thesaurus and describe how he actually is like do we need to do something more or can I make my coffee in peace, what are your eyebrows doing, what is that, are you sure Stiles is okay? Weird _how_ , Derek?

Derek thinks _oh_ , okay, I get it.

Not a vendetta. Not necessarily any less terrifying than a Peter-and-or-Stiles vendetta, but much more manageable.

It takes him the better part of an hour to pry Peter off his back with a crowbar, which is actually the eventual promise to be Peter’s underling in all things Stiles related for the foreseeable future (Peter says week, but nothing Peter has ever done wraps itself up in a week and Stiles takes a week just to get around to his first set of points and this thing definitely very specifically involves both of them). Which. Peter’s underling is not the worst position to be in, Derek thinks, never mind how crazy that would make some people look at him, but it’s _not_.

It does result in him having to get coffee with/for Stiles at a time that is way, way earlier than Derek ever wants to be awake again, _multiple times_. Just to make sure Stiles is all good and dutifully report back to Peter that Stiles is, in fact, better than good, especially given the suspiciously well-timed ‘departures’ of several of Stiles’ more murderous competitors. (Okay, he knows how his looks combine with his sparse vocabulary, but Derek is _not stupid_. ‘Well-timed departure’ is the weakest euphemism for ‘one of those two Machiavellian schemers murdered the shit out of some assholes’ he’s ever heard.)

Despite all previous evidence to the contrary, Derek is capable of being subtle. Like when he is not under constant and immediate threat of death and the stakes are somewhat lower than the constant and immediate deaths of everyone he loves. Being subtle, Derek settles down into morning coffee first with Stiles (something deceptively frothy with as many shots as he can wheedle out of the barista) and then with Peter (just straight espresso from their machine until he feels less like murdering Peter’s way-too-well-groomed face, he needs all the caffeine he can get to be up this early so regularly, swear on all that is holy) and plays good little underling to them both.

As good as he can be, anyways, because while Derek hates the world a little less now that the world seems to hate him a little less—and being very clear, Derek was not the first one to give in that particularly suicidal game of chicken because he is a Hale and Hales have never once in their entire existence dropped a grudge first, even if the other side doesn’t know about said grudge or even possess sentience in the first place—all of this is still happening at just absurd hours of the morning. Absurd to the point that Derek now knows the hours of more overnight diners than early morning coffee places.

And while Peter and Stiles are so busy not-looking at each other, Derek gets to underling…ing.

To Peter he passes on Stiles’ every complaint about the difficulty of getting set up in a business largely defined by how long you can successfully avoid getting cursed to death, as well as his own thoughts on who might eventually get around the doing the cursing cleverly disguised as Stiles’ own thoughts on his so-called peers (mostly by virtue of adding as many descriptive words as Derek can come up with and/or google—Peter will literally never catch on). Derek realizes he’s basically setting up a whole bunch of people to get murdered to death, but it really does seem like beyond probably eventually gunning for Stiles they deserve it? High-end magic really seems to attract and/or bring out the worst. Which is too bad, because a lot of what Stiles does or tries to do is super interesting outside of its more murder-and-madness applications.

To Stiles, he casually mentions the high-octane insanity coffee beans that Peter only uses after staying up all night doing Peter Stuff (which is _murder_ , which Peter is _still_ not telling Derek about, the asshole), the specific and insane Irish granny who knits Peter’s favourite cashmere sweaters, Peter’s best leatherworker who can make everything from lambskin driving gloves to heavy-duty restraints that do great double duty for both sex and murder (well, he doesn’t go so far as to actually mention the more interesting stuff, but with Stiles’ skills on the internet it’s not a hard leap to make), and the only carwash in town that’ll do due diligence on hard-to-reach bloodstains without asking questions (it’s run by ghouls, something about magical blood-seeking saliva, Derek has to bribe them with a bunch of stolen bodies from the morgue and some evidence contamination for the no-questions-asked bit, it’s fine, Stiles seems personally excited about that one).

The ‘casual’ part of bringing these things up is easier than Derek is anticipating because Stiles is just one step shy of interrogating Derek some mornings, and pre-caffeine-sluggishness has a remarkable resemblance to confused reluctance that Derek really does appreciate and does not liberally abuse. Really. The amount of time it would take to get through one of Stiles’ questions, let alone tangents, is too much time to go both awake and without coffee for.

Look, Derek is just helping, and besides it is funny how clueless they both can be. He’s gotta do something with his time, right?

Things slide into a comfortable state of equilibrium that seems like it is not going to change for love or money just long enough that Derek seriously starts to consider locking Peter and Stiles in a closet or something and just seeing what happens (he doesn’t, though, because Peter essentially being Stiles’ sugar baby turns out to be wildly beneficial for Derek as well—thank you, Irish granny whose sweaters are the softest, cloudiest, best-smelling things in the world, Derek loves her and steals them out of Peter’s laundry to keep under his pillow—and Stiles’ list of enemies is really almost offensively cross-referenceable to Derek’s own list of enemies even after thorough vetting, so they’re both winning while Peter gets his murder game on).

And then, without any warning whatsoever beforehand for Derek, Stiles and Peter get on the same page and compare notes, likely either as foreplay or post-coital sweet nothings or, you know, even straight-up dirty talk, Derek can’t tell.

All he can tell is that they both positively reek of sex and are no longer watching each other—they are, in fact, pretty intensely and specifically watching _Derek_ , who just woke up, is wearing one of the insane Irish granny’s sweaters, and is thoroughly addicted to at least three morning espressos by now and therefore at minimum functionality and really has no idea what is going on and why they even got out of bed when it is so far past the point they should have first gotten into bed, so to speak, and is Stiles wearing Peter’s briefs? Oh. Huh, wow—

Stiles has a vividly dark bruise with Peter’s teeth imprinted into it just wrapped right around the side of his neck and he wants to know if Derek is the one who was providing Peter with such a thoughtful and really _very_ thorough and astonishingly intuitive list of Stiles’ enemies who needed to be murdered and/or maimed, because Stiles certainly hadn’t been documenting potential threats so lovingly or exhaustively, being more of a hit-‘em-when-they-come-for-you kind of guy himself, and while he can’t be certain what was said at their routine coffee dates _before_ he got coffee into his bloodstream, he does remember everything else and who else both could and would have done it?

And _Peter_ is not bruised anywhere Derek can see—which is a lot, look at all that—but his hair is utterly disheveled and he is wearing the exactly smug expression he gets when he has been thoroughly debauched, look, Derek lives with him some things you just learn, okay, and he wants to know how Stiles knew so many of the more hidden indulgences of Peter’s life, never _mind_ the custom leather and bespoke clothing (you can get more than just suits, Derek has learned, you can get bespoke _everthing_ ), those things are easy and practical besides, but the best truffles Peter knows and lusts after near continuously? The exact strain of heirloom garlic Peter likes but could never get because only one place in the world grew it and they vet their clients in very weird ways and Peter really had thought that everyone aware of that was dead, but look how close it turned out Derek was paying attention? And isn’t that just the most sneaky thing Derek has ever done, and Peter is just so _proud_ —

And, well, he knew Peter’d be proud, didn’t he, Derek thinks somewhat hysterically, as Stiles and Peter stalk him through the apartment in uncanny synch until he trips backwards over the couch and when he falls they _both_ catch him, and, wow, they’re—they’re just really close to his face, and it’s kind of a lot, and he doesn’t actually have any plans for what to do if they actually get around to figuring themselves out, let alone what he has been doing this whole time—

Stiles is smirking like he is the sole owner of the best secret in the world. Peter has been courting him with fine-tuned, alibi-included murder, he informs Derek with no small amount of glee, and when you take a step back from it all it really looks rather suspiciously like Derek has been courting them _both_ with the most under-handed underlinging Stiles has ever had the pleasure of witnessing.

Derek blushes all the way down to his toes and somehow both a) realizes that is exactly what he has been doing this whole time, oh my god, how did he not know that before Stiles and Peter knew that, the sweater he is wearing _right now_ smells more like Peter and Stiles than any Irish granny and he is _wearing it_ after stealing it from Peter in the first place and b) verifies that is exactly what he has been doing for Stiles and Peter so that they are now _both_ kissing him, messy and hungry and fighting over taking turns, finally just sharing his mouth in a very coordinated display that Derek is glad he doesn’t have to have any control over seeing as he has already lost track of whose tongue is where.

Actually, Derek loses track of everything for a hot minute.

Turns out being played like fiddles by Derek is a major turn on for both Stiles and Peter and they take great and immediate relish in catching up on all the time they lost just going after each other when they could have also been going after Derek if they had just known ( _Derek_ didn’t even know). Derek has never had such good or thorough sex in his life, ruined couch and Peter and Stiles comparing notes _again_ on his scheming—their words—over his head aside.

So it was the straight-up dirty talk option, that’s fine, as long as Derek doesn’t have to participate; Peter seems more happy with what he’s doing with his mouth over any more input from Derek anyways, which is good, because Derek is still blushed down to his toes he can just tell, and Stiles is pretty deep into both an awed monologue pulling all Derek’s manipulations together and Derek himself, so, really, everyone’s good.

Derek is also now Peter’s permanent favourite underling (officially, he already knew that, and besides, Stiles would never go for an underling position) and Stiles’ business manager (which includes everything from accounting to a specific branch of advanced blood-and-sex magic quote ‘now that that’s an option’ unquote, so, you know, never boring).

He is very good at both positions—and others aside—and very happy with how things played out, especially finally getting to sleep in again now that Peter and Stiles can skip the middle man and argue from bed (metaphorically skip the middle man, anyways, since Derek is literally in the middle now more often than not).

**Author's Note:**

> [The best truffles I know and lust after near continuously](https://www.choicolate.com/)   
>  _and they ship and it's winter yessssssssss_


End file.
